The present invention relates to a control system using an angular velocity detecting sensor with drift, and particularly relates to an apparatus for canceling drift in such an angular velocity detecting sensor so that occurrence of drift of the entire control system due to the drift of the angular velocity detecting sensor can be prevented.
In various sensors, generally, drift occurs in their outputs. Temperature drift due occurs to variations in temperature characteristics of elements constituting the sensors,and occur due to variations in environmental temperature and self heat generation; Time drift occurs which is drift appearing in sensor outputs with the passage of operation time.
In the case where a control system is constituted by using an angular velocity detecting sensor with such drift, conventionally, the influence of drift of the angular velocity detecting sensor on the whole of the control system is suppressed by making the output of the sensor pass through an AC coupler or the like to nullify the control gain in a DC zone of a control band to thereby suppress the control gain in the time region of drift.
The above measure to cope with such drift as mentioned above is conventionally well known.
In such an above measure in which the output of an angular velocity detecting sensor is taken out through an AC coupler so as to reduce the influence of drift, however, the gain in a DC zone of the control band falls and it is therefore impossible to apply this measure to an object to be controlled which requires control to be carried out also in the DC zone. In such an above measure, therefore, there is a problem that the field of application of angular velocity detecting sensors is limited.